In the 1950's, as the popularity and decibel level of boating increased,
the state slightly modified the "silence is golden" rule when it established
excessive motorboat noise laws.

State motorboat laws, like laws for cars, motorcycles, trailbikes, and
snowmobiles, prohibit excessive noise. All of these laws are aimed at reducing
high, offensive noise levels so that everyone may enjoy a better
quality of life.

MUFFLE IT FOR YOUR HEALTH

There is no illness known to be directly caused by noise, except of
course, the serious problem of hearing loss. Yet throughout dozens of studies,
noise has been clearly identified as an important cause of physical and
psychological stress, and stress has been directly linked to many of our
most common health problems--heart disease, high blood pressure, headaches,
and fatigue.

NOISE LAWS

The boating law states that engine exhaust shall be effectively muffled
at all times to prevent excessive or unusual noise. Noise-level limits
for boats operating on inland water are as follows:

82 decibels for engines manufactured on or after January 1, 1978.

84 decibels for engines manufactured on or after January 1, 1976 and before
January 1, 1978.

86 decibels for engines manufactured before January 1, 1976.

A boat's noise level can be measured by testing on a set course when conditions
warrant, and operators can be cited if their boats exceed legal noise levels.
A citation may also be issued without a sound level test when, in the
judgment of the officer, a boat is emitting excessive or unusual noise.

COMMON SOUND LEVELS

Below is a graph describing decibel-dB(A) levels for some common noise
sources. A quiet boat is typically 75-80 dB(a) measured at a distance of
50 feet.